vuex-i18n

This is a fork from vuex-i18n with enhancements for vue3. The plugin can be used as Plugin or as Composition API.

Simple example applications for both, as plugin and as composition API can be found in the examples folder. Both examples use vite as build tool. Run apps via npm run dev.

The APIs remain largley unchanged with the main different being the removal of translation filters. Filters are not supported in vue 3.

Requirements

• Vue ^3.0.0
• Vuex ^4.0.0-rc.1 (or newer)

Installation

$ npm install @unify/vuex-i18n

Setup

The vuex-i18n plugin is intended to be used for applications that use vuex as store and require localized messages. Make sure that both vue and vuex have been loaded beforehand.

The plugin provides a vuex module to store the localization information and translations and a plugin to allow easy access from components.

The plugin does not make any assumption on how you want to load the localization information. It can be loaded on start in your application bundle or dynamically after when the user is switching to a different language.

Use as Plugin

// main.js
import { createApp } from 'vue'
import { createStore } from 'vuex'
import { createI18nPlugin, useI18nPlugin } from '@unify/vuex-i18n'
import App from './App.vue'

const app = createApp(App)
const store = createStore({})
app.use(store)

// Create i18n plugin with store as first paramter
app.use(createI18nPlugin(store/*, config */))

// Set translations and locale
const i18n = useI18nPlugin()
i18n.add('en', { title: 'My Title'})
i18n.set('en')

app.mount('#app')

<!-- App.vue -->
<template>
  <div>{{ $t('title') }}</div>
</template>
<script>
export default { name: 'App' }
</script>

Use as Composition API

// main.js
import { createApp } from 'vue'
import { createStore } from 'vuex'
import App from './App.vue'

const app = createApp(App)
app.use(createStore({}))
app.mount('#app')

<!-- App.vue -->
<template>
  <div>locale is: {{ locale() }}</div>
  <div>{{ t('title') }}</div>
</template>
<script>
import { provideI18n, useI18n } from '@unify/vuex-i18n'

export default {
  name: 'App',
  setup() {
    // Add translations and set language
    const i18n = provideI18n(/* config */)
    i18n.add('en', { title: 'My Title'})
    i18n.set('en')

    // Child components can access i18n via useI18n, but since this
    // is the same component where provide is used, use the i18n var
    const { translate: t, locale } = i18n  // useI18n()
    return { t, locale }
  }
}
</script>

Detailed usage

You can specify a custom module name for vuex (default is 'i18n') or a callback that is triggered when a key has no translation for the current locale. Please note, that the function supplied for onTranslationNotFound will be called if the key is not in the actual locale or a parent locale (ie. en for en-us), however, the key might still be available in the fallback locale.

If a return value is given, this will be used as translation text for the key that was not found. It is also possible to return a promise. This will allow you to dynamically fetch the data from an api. Be aware, that the key will only be resolved once and then written like any other key into the store. Therefore subsequent calls of the same key will not trigger the onTranslationNotFound method.

// without return value (will use fallback translation, default translation or key)
app.use(createI18nPlugin(store, {
  moduleName: 'i18n',
  onTranslationNotFound (locale, key) {
    console.warn(`i18n :: Key '${key}' not found for locale '${locale}'`);
  }}
));

// with string as return value. this will write the new value as translation
// into the store
// note: synchronous resolving of keys is not recommended as this functionality
// should be implemented in a different way
app.use(createI18nPlugin(store, {
  moduleName: 'i18n',
  onTranslationNotFound (locale, key) {
    switch(key) {
    case: '200':
      return 'Everything went fine';
      break;
    default:
      return 'There was a problem';
    }
  }}
));

// with promise as return value. this will write the new value into the store,
// after the promise is resolved
Vue.use(createI18nPlugin(store, {
  moduleName: 'i18n',
  onTranslationNotFound (locale, key) {
    return new Promise((resolve, reject) => {
      axios.get('/api/translations/async', {locale: locale, key:key})
      .then((result) => {
        resolve(result.data);
      }).catch() {
        reject();
      }
    })
  }}
));

Config

You can pass a config object as the third parameter when use vuex-i18n. i.e. Vue.use(vuexI18n.plugin, store, config)

At present, the configuration options that are supported are as follows:

• moduleName (default i18n)
• identifiers (default ['{', '}'])
• preserveState (default false)
• onTranslationNotFound (default function(){})
• warnings: default(true)

const config = {
  moduleName: 'myName'
}

app.use(createI18nPlugin(store, config))

Usage

vuex-i18n provides easy access to localized information through the use of the $t().

The plugin will try to find the given string as key in the translations of the currently defined locale and return the respective translation. If the string is not found, it will return as is. This wil allow you to setup an application very quickly without having to first define all strings in a separate template.

It is also possible to specify a fallback-locale $i18n.fallback(locale). If the key is not found in current locale, vuex-i18n will look for the key in the fallback-locale. If the key can not be found in the fallback-locale either, the key itself will be returned as translation.

<div>
  // will return: "Some localized information"
  {{ $t('Some localized information')}}
</div>

In larger projects, it is often easier to use a more robust translation key instead of the default text. Therefore it is also possible to specify the key and default translation. The default value will only be used, if the key cannot be found in the current and in the fallback locale.

<div>
  // will return: "Default information text" if the key non.existing.key is
  // not specified in the current and the fallback locale
  {{ $t('non.existing.key', 'Default information text')}}
</div>

Dynamic parameters that can be passed to the translation method in the form of key/value pairs.

<div>
  // will return: "You have 5 new messages"
  {{ $t('You have {count} new messages', {count: 5}) }}
</div>

It is possible to specify custom identifiers for variable substitutions. The respective identifiers - start and stop - must be passed when initializing the module. Please note that a regular expression is used to match the tags. Therefore it might be necessary to escape certain characters accordingly.

// i.e. to use {{count}} as variable substitution.
app.use(createI18nPlugin(store, {
  identifiers: ['{{','}}']
}));

Basic pluralization is also supported. Please note, that the singular translation must be specified first, followed by plural translations denoted by :::. Up to six pluralization forms are supported based on configuration taken from vue-gettext. The second option is used for variable replacements. The third option to define if the singular or pluralized translation should be used (see below for examples).

<div>
  // will return: "You have 5 new messages" if the third argument is 5"
  // or "You have 1 new message" if the third argument is 1
  // or "You have 0 new messages" if the third argument is 0 (note pluralized version)

  // using the translation directly (as specified in the current readme)
  {{ $t('You have {count} new message ::: You have {count} new messages', {count: 5}, 5) }}


  // using a key to lookup the translations
  {{ $t('mykey', {count: 5}, 5) }}

  // in the store
  const translations = {
    'mykey': 'You have {count} new message ::: You have {count} new messages'
  }

  // alternative specification with array for translations
  const translations = {
    'mykey': [
      'You have {count} new message',
      'You have {count} new messages'
    ]
  }
</div>

<div>
  // In case when there are more than singular and plural versions like in Latvian language.
  // will return: "5 bērni" (in english - 5 children) if the third argument is 5"
  // or "2 bērni" if the third argument is 2
  // or "1 bērns" if the third argument is 1
  // or "0 bērnu" if the third argument is 0
  {{ $t('{count} bērns ::: {count} bērni ::: {count} bērnu', {count: 5}, 5) }}
</div>

The current locale can be set using the $i18n.set() method. By default, the translation method will select the pre-specified current locale. However, it is possible to request a specific locale using the $tlang() method.

<div>
  // will return the english translation regardless of the current locale
  {{ $tlang('en', 'You have {count} new messages', {count: 5}) }}
</div>

There are also several methods available on the property this.$i18n or Vue.i18n

// translate the given key
$t(), i18n.translate()

// translate the given key in a specific locale, also available as filter
// i.e {{ 'message' | translateIn('en') }}
i18n.translateIn()

// get the current locale
i18n.locale()

// get all available locales
// is is however recommended to use a computed property to fetch the locales
// returning Object.keys(this.$store.state.i18n.translations); as this will
// make use of vue's caching system.
i18n.locales()

// set the current locale (i.e. 'de', 'en')
i18n.set(locale)

// add locale translation to the storage. this will extend existing information
// (i.e. 'de', {'message': 'Eine Nachricht'})
i18n.add(locale, translations)

// replace locale translations in the storage. this will remove all previous
// locale information for the specified locale
i18n.replace(locale, translations)

// remove the given locale from the store
i18n.remove(locale)

// set a fallback locale if translation for current locale does not exist
i18n.fallback(locale)

// check if the given locale translations are present in the store
i18n.localeExists(locale)

// check if the given key is available (will check current, regional and fallback locale)
i18n.keyExists(key)

// optional with a second parameter to limit the scope
// strict: only current locale (exact match)
// locale: current locale and parent language locale (i.e. en-us & en)
// fallback: current locale, parent language locale and fallback locale
// the default is fallback
i18n.keyExists(key, 'strict'), i18n.keyExists(key, 'locale'), i18n.keyExists(key, 'fallback'),

Contributions

Any comments or suggestions are very welcome.